Microbiology practice exam 4

What is the role of the genes related to the F factor in conjugation?

A) Aid in DNA transfer B) Forms sex pili C) Includes IS elements that assist plasmid integration into the host cell's chromosome

Which of the following conditions must be met for transformation to take place?

A) Bacteria must be in exponential phase of growth

Which of the following is a mechanism of horizontal gene transfer (HGT) in Bacteria and Archaea?

A) Conjugation B) Transformation C) Transduction

Which of the following is the end product of bacterial transformation?

A) DNA is degraded by the host cell B) Integration of the DNA by non-reciprocal recombination C) Plasmid is stably transformed into the cell but separate from the chromosome

11. Microbial mutants can be identified and selected by

A) Growing cells on minimal media B) Growing cells in the presence of viruses C) Growing cells on an alternative carbon source D) All of the above

A reciprocal exchange between a pair of DNA molecules with the same nucleotide sequence is called

A) Homologous recombination

What happens to donor DNA when it enters the recipient cell?

A) Integration of the DNA into the recipient's chromosome B) Replicates separately from the host DNA in a plasmid C) Donor DNA remains in the cytoplasm, unable to replicate

Which of the following is true of conjugation?

A) Requires physical contact between microbes B) Unidirectional C) Involves plasmids

Which DNA repair mechanism is highly error prone and results in the generation of numerous mutations?

A) SOS response

A change in the nucleotide sequence of a codon that does not change the amino acid encoded by that codon is called a

A) Silent mutation

Mutations occur

A) Spontaneously, B) In response to physical or chemical agents

Mutations allowing for substitution of a purine for a pyrimidine or vice versa is called a

A) Transversion mutation

Transposable elements can produce which of the following effects?

A) Turns genes on or off B) Inserts a start or stop codon in the middle of a gene C) Mutations occur

In which DNA repair mechanism is the damaged portion of DNA removed and the intact complementary strand used as a template for synthesis of new DNA?

B) Excision repair

Conjugation in which the donor transfers chromosomal genes with great efficiency but does not change the recipient into F+ cells is known as

B) HFr conjugation

The phage genome is passively replicated by the host in which of the following cycles?

B) Lysogenic cycle only

Which type of mutation involves a single base substitution that changes a codon for one amino acid into a codon for another?

B) Missense mutation

Which technique is used to screen for auxotrophic mutants?

B) Replica plating

A specific portion of the bacterial genome is carried by transducing particles in

B) Specialized transduction

The uptake of DNA from one bacterial cell, either as a plasmid or as a fragment, by another cell is called

B) Transformation

Mutations allowing for substitution of one purine for another or one pyrimidine for another is called a

B) Transition mutation

Mobile genetic elements that contain genes in addition to those required for transposition are called

B) Transposons

The transfer of a plasmid from one cell to another via direct contact is known as

C) Conjugation

Which of the following is true of replicative transposition?

C) Contains genes coding for transposase and resolvase

Which type of DNA repair mechanism repairs thymine dimers by splitting them with the help of visible light?

C) Direct repair

Mutagens that distort DNA to induce a single nucleotide pair insertion or deletion are known as

C) Intercalating agents

Which of the following is true of insertion sequences of transposable elements?

C) It contains only the gene for the enzyme transposase

What type of mutation converts a sense codon, one coding for an amino acid, to a nonsense codon (i.e., a stop codon)?

C) Nonsense mutation

What is the purpose of the Ames Test?

C) To determine if a substance is a mutagen

Bacterial gene transfer mediated by viruses is known as

C) Transduction

Lysine auxotrophs

D) Are unable to produce lysine, and can only grow on media with lysine added

Horizontal gene transfer (HGT) mechanisms enable creation of recombinants in

D) Both Bacteria and Archaea

The insertion or deletion of one or two base pairs within the coding region of a gene results in a

D) Frameshift mutation